The Chamber announced Tuesday that it will back Minnick for a second term in Idaho's 1st District, shoring up his reelection fight against state Rep. Raul Labrador. The organization's political director, Bill Miller, explained in a statement: "On issues ranging from competition in the health care industry, to lowering taxes, to reducing energy costs, Idaho's businesses and workers have a tireless advocate in Walt Minnick."

It's the latest in a series of conservative seals of approval that Minnick has won: he's also the sole Democrat the Tea Party Express is backing this year, and is among the highest-rated members of his party in the anti-tax Club for Growth's lawmaker rankings.

Minnick spokesman John Foster trumpeted the Chamber's endorsement as a sign that the congressman, a former Nixon administration official, is an authentic center-right Democrat.

"Some folks in Walt's position are accused of posturing on core fiscal issues, but the tea party endorsement gave us just a bit more credibility in the eyes of some," he said. "It's further proof that Walt's not just talking about this stuff — he's actually committed to doing the things that generated a record worthy of endorsement by the Chamber."

Labrador, Minnick's challenger, was the upset winner of a GOP House primary against veteran Vaughn Ward, a candidate initially favored by national Republicans and endorsed by former Alaska Gov. Sarah Palin. Labrador has attacked Minnick repeatedly for supporting House Speaker Nancy Pelosi's leadership and not doing enough to rein in spending.

Minnick has voted against his party time and again, however, opposing the health care reform law, cap and trade legislation and the stimulus bill.